CHAPTER 6: Scatter plot, Correlation, and Line of Best Fit

Transcription

1 CHAPTER 6: Scatter plot, Correlation, and Line of Best Fit Name: Date: 1. A baseball coach graphs some data and finds the line of best fit. The equation for the line of best fit is y = 0.32x.51, where x is the number of times at bat and y is the number of hits. 3. The graph below shows the relationship between the distance in miles a delivery truck traveled and the number of hours each delivery took. How many hits should he expect from a player who is at bat 175 times? A) 35 hits B) 49 hits C) 9 hits D) 62 hits 2. Below is the table of data regarding the cherry blossom trees in Washington D.C. A) Make a scatter plot of the given data. Average Temp ( C) Date in April trees bloom Which of the two given points would be the best to use to calculate the line of best fit? A) (500, 11) and (700, 11) B) (300, 9) and (0, 7) C) (0, 9) and (500, 11) D) (300, 7) and (0, 10) 4. Chang wants to know if he is improving his skill on the cello. He created a scatter plot and drew a line of best fit. B) Correlation: The equation of the line of best fit is... A) y = -2.17x C) y = -0.46x + 9 B) y = 2.17x D) y = -2.17x 9.35

2 5. The graph shows the weights of dogs and the time it took the same dogs to complete an agility course in seconds. Which shows the line of best fit for the data? 6. Which graph represents a positive correlation? A) B) A) C) D) 0 B) 7. The scatter plot below shows the average yearly consumption of bottled water by people in the United States starting in C) 0 D) 0 Using the line of best fit, predict the average consumption of bottled water in the year 00? A) 17 gallons B) 18 gallons C) 19 gallons D) gallons 0

3 8. The table below shows the sales for a flower company for the years 07 through 12. A) Graph the data on the scatter plot and draw a line of best fit. FLOWER SALES Sales Year (in thousands) 07 $ $ $ $ $ $4 B) Write an equation for the line of best fit for this data. Let x represent the years since 07 and y represent the sales, in thousands of dollars. C) According to your equation, in what year will the sales reach about $500 (in thousands)? 9. Mr. Van made a graph to represent the time his students spent studying for their test and their actual test score. Which is the correct equation for the line of best fit? A) y = 1.4x + 55 B) y = 1.4x 84 C) y = 0.72x + D) y = Which relationship is shown by this scatter plot? Number of new gym memberships sold Cost of gym membership A) As the cost goes down, the number sold goes down. B) As the cost goes up, the number sold goes down. C) As the cost does down, the number sold remains the same. D) There is no relationship between cost and the number sold.

4 11. Given in the table and scatter plot are the samplings of average annual temperatures collected at different elevations in the United States. Pick two points from the line of best fit and determine the equation for the line of best fit. Average Elevation Annual (meters) Temp ( C) 1, , , , ,0 15 2, , Which graph represents the correlation of its given situation correctly? A) B) C) D) Amount of dog food Number of tourists flying to Hawaii Number of people going swimming Amount of clothing sold Size of the dog Cost of plane Temperature Number of customers at clothing store 13. The following data table and scatter plot represent the number of negative customer reviews for a given model of cell phone and the total number of that same cell phone model that were sold. Answer the following. Number of consumer negative reviews Number of cell phones sold (in thousands) TRUE OR FALSE: A) Points (37,890) and (98,505) are on the line of best fit: B) This scatter plot represents a negative correlation: C) It s reasonable to predict that if there are 75 negative reviews the number of cell phones sold of that same model will be close to 0,000.

5 14. Below is the number of clothes donated to New York City homeless shelters in the given years. 15. A keyboarding instructor at a community college collected data comparing a student s age and their typing speed. The equation for the line of best fit is given as y = -1.4x , where x is the age in years and y is the typing speed. A) If you are 25 years of age, what is your typing speed? B) Is the typing speed increasing or decreasing as the student gets older? Explain. A) Determine the equation for the line of best fit using the given two points on the line of best fit, where x is the number years since 1992 and y is the number of clothes donated in thousands. 16. At the Happy Paper company the more boxes of paper you order the cheaper the price you have to pay for each box of paper. Below are the prices charged per box of paper to different companies ordering various quantities of paper. B) Using the equation for the line of best fit predict the year in which only 38,000 items of clothing will be donated to the homeless shelters in New York City. C) Is a solid line appropriate in the graph? Explain. A) Using the line of best fit, if your company wants to only pay $5.05 for each box of paper, how many boxes of paper should be ordered from Happy Paper company? B) Is a solid line appropriate? Explain.

6 17. The table below shows the cost of flying from San Francisco to various other cities in the United States. There is a relationship between the distance you are flying and the cost of your plane ticket. The data from the table is represented on the scatter plot. Distance(miles) , , 950 1, Cost of the plane ticket ($) Cost of plane ticket ($) A) Draw a line of best fit and pick two good points from the table that are on your line: B) Determine the equation for the line of best fit Distance (miles) 18. The table below shows how much water Nuria drinks and the average temperature for that day. A) Create a scatter plot for the given data. Temp (F ) Water consumed in a day (oz) B) What is the correlation? 19. Determine the correlation for each statement. A) The number of people at your party and the number of sodas you have in the refrigerator. B) The amount your drive to school and the amount you have to pay for gas. C) The size of your dog and the number of times you take it to the vet.. The table below represents the number of boats registered in the given year. Year Boat Registrations (thousands) The equation for the line of best for the data is given as y = 27x + 751, where x is the years since 1996, and y is the total boat registrations. Using the given equation for the line of best fit, predict the number of boat registrations for 15.